mass
Module¶
All mass elements are defined in this file. This includes:
- CMASS1
- CMASS2
- CMASS3
- CMASS4
- CONM1
- CONM2
All mass elements are PointMassElement and Element objects.
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class
pyNastran.bdf.cards.elements.mass.
CMASS1
(eid, pid, nids, c1=0, c2=0, comment='')[source]¶ Bases:
pyNastran.bdf.cards.elements.mass.PointMassElement
Defines a scalar mass element.
1 2 3 4 5 6 7 CMASS1 EID PID G1 C1 G2 C2 Creates a CMASS1 card
Parameters: - eid : int
element id
- pid : int
property id (PMASS)
- nids : List[int, int]
node ids
- c1 / c2 : int; default=0
DOF for nid1 / nid2
- comment : str; default=’‘
a comment for the card
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Centroid
(self)[source]¶ Centroid is assumed to be c=(g1+g2)/2. If g2 is blank, then the centroid is the location of g1.
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_properties
= ['node_ids']¶
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classmethod
add_card
(card, comment='')[source]¶ Adds a CMASS1 card from
BDF.add_card(...)
Parameters: - card : BDFCard()
a BDFCard object
- comment : str; default=’‘
a comment for the card
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cross_reference
(self, model)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
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node_ids
¶
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safe_cross_reference
(self, model, xref_errors)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
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type
= 'CMASS1'¶
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class
pyNastran.bdf.cards.elements.mass.
CMASS2
(eid, mass, nids, c1, c2, comment='')[source]¶ Bases:
pyNastran.bdf.cards.elements.mass.PointMassElement
Defines a scalar mass element without reference to a property entry.
1 2 3 4 5 6 7 CMASS2 EID M G1 C1 G2 C2 Creates a CMASS2 card
Parameters: - eid : int
element id
- mass : float
mass
- nids : List[int, int]
node ids
- c1 / c2 : int; default=None
DOF for nid1 / nid2
- comment : str; default=’‘
a comment for the card
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Centroid
(self)[source]¶ Centroid is assumed to be c=(g1+g2)/2. If g2 is blank, then the centroid is the location of g1.
-
_properties
= ['node_ids']¶
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classmethod
add_card
(card, comment='')[source]¶ Adds a CMASS2 card from
BDF.add_card(...)
Parameters: - card : BDFCard()
a BDFCard object
- comment : str; default=’‘
a comment for the card
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cp_name_map
= {'M': 'mass'}¶
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cross_reference
(self, model)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
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node_ids
¶
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repr_fields
(self)[source]¶ Gets the fields in their simplified form
Returns: - fields : List[varies]
the fields that define the card
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safe_cross_reference
(self, model, xref_errors)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
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type
= 'CMASS2'¶
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class
pyNastran.bdf.cards.elements.mass.
CMASS3
(eid, pid, nids, comment='')[source]¶ Bases:
pyNastran.bdf.cards.elements.mass.PointMassElement
Defines a scalar mass element that is connected only to scalar points.
1 2 3 4 5 CMASS3 EID PID S1 S2 Creates a CMASS3 card
Parameters: - eid : int
element id
- pid : int
property id (PMASS)
- nids : List[int, int]
SPOINT ids
- comment : str; default=’‘
a comment for the card
-
_properties
= ['node_ids']¶
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classmethod
add_card
(card, comment='')[source]¶ Adds a CMASS3 card from
BDF.add_card(...)
Parameters: - card : BDFCard()
a BDFCard object
- comment : str; default=’‘
a comment for the card
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cross_reference
(self, model)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
-
node_ids
¶
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type
= 'CMASS3'¶
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class
pyNastran.bdf.cards.elements.mass.
CMASS4
(eid, mass, nids, comment='')[source]¶ Bases:
pyNastran.bdf.cards.elements.mass.PointMassElement
Defines a scalar mass element that is connected only to scalar points, without reference to a property entry
1 2 3 4 5 CMASS4 EID M S1 S2 Creates a CMASS4 card
Parameters: - eid : int
element id
- mass : float
SPOINT mass
- nids : List[int, int]
SPOINT ids
- comment : str; default=’‘
a comment for the card
-
_properties
= ['node_ids']¶
-
cp_name_map
= {'M': 'mass'}¶
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cross_reference
(self, model)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
-
node_ids
¶
-
type
= 'CMASS4'¶
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class
pyNastran.bdf.cards.elements.mass.
CONM1
(eid, nid, mass_matrix, cid=0, comment='')[source]¶ Bases:
pyNastran.bdf.cards.elements.mass.PointMassElement
Concentrated Mass Element Connection, General Form Defines a 6 x 6 symmetric mass matrix at a geometric grid point
1 2 3 4 5 6 7 8 9 CONM1 EID G CID M11 M21 M22 M31 M32 M33 M41 M42 M43 M44 M51 M52 M53 M54 M55 M61 M62 M63 M64 M65 M66 Creates a CONM1 card
Parameters: - eid : int
element id
- nid : int
the node to put the mass matrix
- mass_matrix : (6, 6) float ndarray
the 6x6 mass matrix, M
- cid : int; default=0
the coordinate system for the mass matrix
- comment : str; default=’‘
a comment for the card
- ::
- [M] = [M11 M21 M31 M41 M51 M61]
[ M22 M32 M42 M52 M62] [ M33 M43 M53 M63] [ M44 M54 M64] [ Sym M55 M65] [ M66]
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_properties
= ['node_ids']¶
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classmethod
add_card
(card, comment='')[source]¶ Adds a CONM2 card from
BDF.add_card(...)
Parameters: - card : BDFCard()
a BDFCard object
- comment : str; default=’‘
a comment for the card
-
cross_reference
(self, model)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
-
node_ids
¶
-
repr_fields
(self)[source]¶ Gets the fields in their simplified form
Returns: - fields : List[varies]
the fields that define the card
-
safe_cross_reference
(self, model, xref_errors)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
-
type
= 'CONM1'¶
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class
pyNastran.bdf.cards.elements.mass.
CONM2
(eid, nid, mass, cid=0, X=None, I=None, comment='')[source]¶ Bases:
pyNastran.bdf.cards.elements.mass.PointMassElement
1 2 3 4 5 6 7 8 CONM2 EID NID CID MASS X1 X2 X3 I11 I21 I22 I31 I32 I33 CONM2 501274 11064 132.274 Creates a CONM2 card
Parameters: - eid : int
element id
- nid : int
node id
- mass : float
the mass of the CONM2
- cid : int; default=0
coordinate frame of the offset (-1=absolute coordinates)
- X : (3, ) List[float]; default=None -> [0., 0., 0.]
xyz offset vector relative to nid
- I : (6, ) List[float]; default=None -> [0., 0., 0., 0., 0., 0.]
mass moment of inertia matrix about the CG I11, I21, I22, I31, I32, I33 = I
- comment : str; default=’‘
a comment for the card
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Centroid
(self)[source]¶ This method seems way more complicated than it needs to be thanks to all these little caveats that don’t seem to be supported.
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Centroid_no_xref
(self, model)[source]¶ This method seems way more complicated than it needs to be thanks to all these little caveats that don’t seem to be supported.
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I
= None¶ Mass moments of inertia measured at the mass center of gravity in the coordinate system defined by field 4. If CID = -1, the basic coordinate system is implied. (Real) I11, I21, I22, I31, I32, I33 = I
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Inertia
(self)[source]¶ Returns the 3x3 inertia matrix .. warning:: doesnt handle offsets or coordinate systems
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X
= None¶ Offset distances from the grid point to the center of gravity of the mass in the coordinate system defined in field 4, unless CID = -1, in which case X1, X2, X3 are the coordinates, not offsets, of the center of gravity of the mass in the basic coordinate system. (Real)
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classmethod
add_card
(card, comment='')[source]¶ Adds a CONM2 card from
BDF.add_card(...)
Parameters: - card : BDFCard()
a BDFCard object
- comment : str; default=’‘
a comment for the card
-
cid
= None¶ Coordinate system identification number. For CID of -1; see X1, X2, X3 below. (Integer > -1; Default = 0)
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cross_reference
(self, model)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
-
eid
= None¶ Element identification number. (0 < Integer < 100,000,000)
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mass
= None¶ Mass value. (Real)
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nid
= None¶ Grid point identification number. (Integer > 0)
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node_ids
¶
-
repr_fields
(self)[source]¶ Gets the fields in their simplified form
Returns: - fields : List[varies]
the fields that define the card
-
safe_cross_reference
(self, model, xref_errors)[source]¶ Cross links the card so referenced cards can be extracted directly
Parameters: - model : BDF()
the BDF object
-
type
= 'CONM2'¶
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class
pyNastran.bdf.cards.elements.mass.
PointMassElement
[source]¶ Bases:
pyNastran.bdf.cards.base_card.Element
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repr_fields
(self)[source]¶ Gets the fields in their simplified form
Returns: - fields : List[varies]
the fields that define the card
-